Maptraveler101

Hi all, I am looking to locate a family member who is overseas in Thailand. The Thailand Embassy won't give information due to the privacy laws regarding the location of my family member who is a US Citizen. He has lived there for over 20 years and I would like to locate or get information on him. I am open for suggestions on how to collect information on him, or my sister who is half Thai. For clarification, I am also a US Citizen.